The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingRear brake
Components
Removal
Hint:
Use the same procedures for the lh side and rh side.
The procedures listed below are for the lh side.
Remove rear wheel
Drain brake fluid
Notice:
Wash off brake fluid immediately if it comes in
contact with any painted surface.
Disconnect rea ...
Key types
The following keys are provided
with the vehicle.
Vehicles without smart key
system
Master keys
Operating the wireless remote control
function
Key number plate
Vehicles with smart key system
Electronic keys
Operating the smart key system
Operating the wireless remote
control function ...
Yaw rate and deceleration sensor
Components
Removal
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
Remove front seat assembly lh
For manual seat: ...